import bug

[MRAB]

Gabriel Genellina wrote:
[snip]
>>> One way to avoid name clashes would be to put the entire standard
>>> library under a package; a program that wants the standard re
>>> module would write "import std.re" instead of "import re", or
>>> something similar. Every time the std package is suggested, the
>>> main argument against it is backwards compatibility.
>> 
>> You could do it in a backwards compatible way, by adding the std
>> package directory into the path.
> 
> Unfortunately you can't, at least not without some special treatment
> of the std package. One of the undocumented rules of the import
> system is that you must not have more than one way to refer to the
> same module (in this case, std.re and re). Suppose someone imports
> std.re; an entry in sys.modules with that name is created. Later
> someone imports re; as there is no entry in sys.modules with such
> name, the re module is imported again, resulting in two module
> instances, darkness, weeping and the gnashing of teeth :) (I'm sure
> you know the problem: it's the same as when someone imports the main
> script as a module, and gets a different module instance because the
> "original" is called __main__ instead).
> 
Couldn't the entry in sys.modules be where the module was found, so that
if 're' was found in 'std' then the entry is 'std.re' even if the import
said just 're'?